19th August 2026
There is something particularly unsettling about a drought.
At first it appears to be a straightforward shortage of rain. The rain stops, the ground dries, rivers fall and reservoirs decline.
But the longer the drought continues, the relationship between the land and the atmosphere can begin to change.
The ground is no longer simply suffering from the weather.
It can begin to influence the weather.
That may sound surprising, but scientists have been studying the relationship between soil moisture, evaporation, cloud formation and temperature for years. New research published in 2026 has reinforced just how important these interactions can be.
The basic process is remarkably straightforward.
When soil contains plenty of water, some of the Sun's energy is used to evaporate that water. Plants also draw moisture from the ground and release it into the atmosphere through transpiration. Together these processes are known as evapotranspiration.
That water enters the atmosphere.
Under the right conditions, atmospheric moisture contributes to cloud formation and eventually precipitation.
There is therefore a natural exchange between the ground and the atmosphere.
Wet ground can help cool the land through evaporation and provide moisture to the atmosphere.
Dry ground behaves differently.
Once soil moisture becomes severely depleted, there is less water available to evaporate. More of the Sun's energy is then used to heat the land rather than evaporate water.
The result can be higher temperatures.
And that creates a vicious circle.
Higher temperatures increase the demand for moisture. The remaining soil water disappears more rapidly. The increasingly dry soil reduces evaporation and evaporative cooling. The ground heats further.
Researchers describe this as a soil-moisture–temperature feedback.
A major study published in February 2026 found that interactive soil moisture has a substantial influence on Northern Hemisphere summer atmospheric circulation. It described two important feedbacks: one linking soil moisture with temperature and another linking soil moisture with precipitation. When soil becomes dry enough to limit evaporation, surface heating increases, cloud cover can decline and the drying can reinforce itself.
This is where the Danish climatologist's observation becomes particularly interesting.
The idea that "dry ground means less moisture available to help make rain" needs some qualification. Britain does not depend upon evaporation from British soil for all of its rainfall. The Atlantic is an enormous source of atmospheric moisture, and weather systems transport water vapour over the country.
So it would be wrong to suggest that once British soil becomes dry, there is simply no moisture left in the atmosphere.
But the land does contribute to the moisture and energy balance of the atmosphere.
And once the soil becomes very dry, that contribution changes.
Recent research has shown that reduced soil moisture can suppress evapotranspiration, increase sensible heating and, in some circumstances, inhibit cloud and precipitation formation. The result can be a feedback in which drought helps maintain the atmospheric conditions that favour further drought.
This is why the distinction between a hot spell and a heatwave matters.
A hot day can be caused by an atmospheric weather pattern.
A persistent heatwave can involve an interaction between the atmosphere and the land beneath it.
The atmosphere brings the initial conditions. The dry land can then help amplify them.
Europe has seen this before. Research into the exceptional European heatwaves of 2019 found that land-atmosphere feedbacks contributed to the intensity of the July event. Soil moisture deficits increased, evaporation decreased and more energy was transferred into heating the atmosphere.
The latest research suggests that these relationships deserve even greater attention as the climate warms.
A study published in Nature Geoscience in July 2026 found that European summer drying since the 1980s has been driven largely by changes in atmospheric circulation, combined with warming that increases evaporative demand and affects precipitation.
That is important because it prevents us from falling into another simplistic explanation.
Not every drought is caused by dry soil.
Not every heatwave is intensified by soil moisture.
Atmospheric circulation remains enormously important, and Europe's weather is influenced by huge systems extending across the Atlantic, Arctic and beyond.
But when the right atmospheric conditions occur over already-dry land, the land can become part of the problem.
And that is precisely why Britain's experience this summer deserves attention.
Official figures showed that by late July England had experienced extremely low rainfall, with only 3 per cent of the long-term average rainfall for the month at that point. River flows had fallen sharply, reservoirs were declining and soil moisture deficits had reached record levels for the time of year across large areas.
The significance of the soil figures is easy to overlook.
People notice reservoirs.
They notice rivers.
They notice brown grass.
But soil moisture is an invisible part of the water system.
And it acts rather like a memory.
A heavy shower today does not necessarily restore months of lost moisture. Likewise, several weeks of dry weather can leave an imprint that persists even after temperatures fall.
This matters because the soil is effectively part of the country's water storage system.
When it is wet, some rainfall infiltrates into the ground and becomes available to plants, rivers and groundwater.
When it is already saturated, further rain can run off rapidly.
When it is severely dried, rainfall can behave differently again, particularly when the soil has become hard or hydrophobic. Heavy rain can run quickly into streams and drainage systems rather than immediately restoring deeper soil moisture and groundwater.
This helps explain one of the strangest features of drought years.
You can have drought and flooding in the same summer.
Rain can arrive heavily enough to cause flooding while the wider landscape remains seriously short of water.
That seems contradictory until we stop thinking about water simply as something falling from the sky.
The real question is what happens to it once it arrives.
Does it infiltrate?
Does it replenish groundwater?
Does it remain in the soil?
Does vegetation absorb it?
Does it fill reservoirs?
Or does it simply run away to the sea?
This is where the coming decades could become increasingly challenging.
A warmer atmosphere can hold more water vapour. Warmer temperatures can increase the demand for moisture from soils and vegetation. At the same time, changing atmospheric circulation can alter where and when rainfall occurs.
The result may not necessarily be less rain everywhere.
It can instead mean less dependable rainfall.
Long dry periods followed by intense rainfall are particularly difficult for water management. Farmers cannot necessarily store enough water for every prolonged dry period. Reservoirs cannot always capture every intense rainfall event. Soil cannot always absorb water quickly enough.
And ecosystems have their own limits.
A river that experiences increasingly violent swings between flood and drought can be very different from the river that existed under a more stable climate.
For Scotland, this is an issue worth watching even if the immediate threat is much smaller than in southern Europe.
We have historically relied upon the assumption that rainfall will keep our rivers, lochs and soils supplied.
But a changing climate could make the timing of rainfall increasingly important.
A country can receive substantial rainfall over a year and still experience severe water stress during the growing season.
That is perhaps the most important lesson from the science.
We should stop imagining the water cycle as a simple journey from cloud to ground to river to sea.
It is a complicated conversation between the ocean, atmosphere, vegetation, soil, groundwater and rivers.
Change one part of that system and the others respond.
The frightening possibility is that extreme heat and drought can sometimes become self-reinforcing.
The sequence can begin with an atmospheric circulation pattern that suppresses rainfall.
The ground dries.
Evapotranspiration falls.
The land loses some of its natural evaporative cooling.
Temperatures rise.
Atmospheric demand for moisture increases.
Vegetation becomes stressed.
Soil moisture falls further.
And under the right conditions, cloud formation and rainfall can be affected.
It is not an endless cycle. A change in the weather pattern can break it. Atlantic moisture can return. Rain can eventually replenish the land.
But the existence of the feedback means that the starting conditions matter.
A landscape that enters summer already suffering from depleted soil moisture may be much more vulnerable to a heatwave than one that begins the season with healthy reserves.
That gives us a very different way of thinking about drought.
The question is not simply whether it will rain next week.
It is whether the land has enough water stored within it to withstand the next period of heat.
And that brings us back to the much bigger water story.
Rivers, reservoirs, groundwater and soil moisture are not separate problems. They are different parts of the same system.
If we allow soils to become increasingly degraded, drain wetlands, remove natural water storage and build economies around maximum water consumption, we make the system less resilient.
Conversely, protecting wetlands, improving soil structure, restoring natural floodplains, increasing water efficiency and allowing landscapes to retain more rainfall can give the system a greater buffer when drought arrives.
Perhaps the most important message from the extraordinary summer of 2026 is therefore not simply that Britain has experienced another heatwave.
It is that the ground beneath our feet is part of the climate system.
When it is wet, it can help moderate heat and participate in the recycling of atmospheric moisture.
When it becomes severely dry, some of those benefits weaken.
The land can become hotter, vegetation can become stressed and the atmosphere-land relationship can begin to work against us.
That does not mean the ground "creates" or "stops" Britain's rain.
But it does mean that once drought becomes severe, the landscape is no longer just a victim of the weather.
It can become one of the forces shaping what happens next.
And if climate change makes severe soil-moisture deficits more common, that could prove to be one of the least visible — and most important — changes in Britain's future climate.